The Impact of Visualizing Uncertainty on Train Trip Selection
Annex
M. Wunderlich, K. Ballweg, and T. von Landesberger
Part I
Study Data and Visualizations
1 Description of the Train Trips
Attribute TO1 TO2 TO3
Departure ≈ b≺a a ≺S b
Arrival a ≺S b, b≺D a b≺a b≺S a, a≺D b
Travel duration a ≺S b, b≺D a b≺a a ≺S b, ≈D
Transfers no transfers 2 in a and b, longer in a 1 in b Delays a’s delay meets deadline (C2) never critical critical transfer
Alternatives none none 1 for b’s transfer
Table 1: Attribute-wise comparison of the two train trips TO1–TO5 per decision situation. (a denotes the first, b the second trip;≈similar for a and b; shorter/earlier with a: a≺b; according to schedule: S; according to (maximum) expected delays: D)
Attribute TO4 TO5
Departure a ≺b ≈
Arrival ≈ a ≺S b, b≺D a
Travel duration b ≺a ≈S, b ≺Da Transfers 2 in b 1 in a and b
Delays never critical critical transfers Alternatives none 1 for each transfer
Table 2: Attribute-wise comparison of the two train trips TO1–TO5 per decision situation. (a denotes the first, b the second trip;≈similar for a and b; shorter/earlier with a: a≺b; according to schedule: S; according to (maximum) expected delays: D)
TO1 Direct influence of train delay on the arrival time: Both train trips depart at the same time and have no transfers. The travel duration with the first connection is shorter according to the schedule while the travel time with the second connection is shorter according to the (maximum) expected delays.
TO2 Influence of delay on transfer time: Departure and arrival times of the two trips are similar whereas the travel duration with the second trip is slightly shorter. Each trip has two transfers.
The transfer durations of the first connection are longer according to the schedule but shorter
TO3 Influence of a critical delay on arrival time via potential miss of a connecting train: The travel duration of the first trip is longer but the trip contains no transfers. The second trip contains one transfer that is also critical, i.e., the connecting train of the second connection might be missed due to the expected delays. If the connecting train is missed, the arrival time of the second trip is before the arrival time of the first trip. If the connecting train is reached, the order of the arrival times is vice versa.
TO4 Trade off between travel duration and transfers: The arrival time of both trips is similar. The first trip contains no transfers but departs earlier, i.e., its travel duration is longer. The second trip contains two transfers but none of them is critical (i.e., the connecting trains will most probably will be reached).
TO5 Influence of arrival time due to critical delay: Each of the trips contains one transfer of equal duration. The connecting trains in both trips might be missed due to the delay of the preceding trains. The arrival time of the first connection is earlier if the connecting train is reached and later otherwise.
2 Visulizations of the Train Trips
Figure 1: Train Trips TO1 displayed with designDcum
Figure 3: Train Trips TO3 displayed with designDcum
Figure 4: Train Trips TO4 displayed with designDcum
Figure 5: Train Trips TO5 displayed with designDcum
Figure 6: Train Trips TO1 displayed with design Dnoncum
Figure 7: Train Trips TO2 displayed with design Dnoncum
Figure 8: Train Trips TO3 displayed with design Dnoncum
Figure 9: Train Trips TO4 displayed with design Dnoncum
Figure 10: Train Trips TO5 displayed with designDnoncum
Figure 11: Train Trips TO1 displayed with designDvis
Figure 12: Train Trips TO2 displayed with designDvis
Figure 13: Train Trips TO3 displayed with designDvis
Figure 14: Train Trips TO4 displayed with designDvis
Figure 15: Train Trips TO5 displayed with designDvis
Figure 16: Train Trips TO1 displayed with designDtext
Figure 17: Train Trips TO2 displayed with designDtext
Figure 18: Train Trips TO3 displayed with designDtext
Figure 19: Train Trips TO4 displayed with designDtext
Figure 20: Train Trips TO5 displayed with designDtext
Part II
Study Results
3 Decisions
T1
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(c) Train connections TO1 and temporal constraint C1
T1
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(d) Train connections TO1 and temporal constraint C2
T2
!"#$"
!%&' !()(%&' !*+,
(g) Train connections TO2 and temporal constraint C1
T2
!"#$"
!%&' !()(%&' !*+,
(h) Train connections TO2 and temporal constraint C2
T3
T3
T4
!"#$"
!%&' !()(%&' !*+,
(c) Train connections TO4 and temporal constraint C1
T4
!"#$"
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(d) Train connections TO4 and temporal constraint C2
T5
!"#$"
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(g) Train connections TO5 and temporal constraint C1
T5
!"#$"
!%&' !()(%&' !*+,
(h) Train connections TO5 and temporal constraint C2
Figure 22: Distribution of the decisions for each situation composed of a set of train connections TO1–TO5 and a temporal constraint C1/C2. The values are relative to the number of answers for each design. Option 1, Option 2, For me, both trips are of equal value, I can not decide based on this depiction, because: [text input], andI don’t know
4 Statistical Evaluation
4.1 Dependence on the Availability of Delay Uncertainty
TheFisher’s Exact Test showed that the decisions on train trip selection significantly depend on the availability of delay uncertainty visualization for eight out of ten decision scenarios (cf. Table 3).
C1 C2
TO1 <0.001 *** <0.001 ***
TO2 <0.001 *** <0.001 ***
TO3 <0.001 *** <0.001 ***
TO4 1 0.281
TO5 <0.001 *** <0.001 ***
Significance levels: p-value<0.001: ***,<0.01: **,<0.05: *
Table 3: P-values according to Fisher’s Exact Test for decisions depending on the availability of delay uncertainty information in the visualization.
4.2 Dependence on the Design of Connection Display
We tested whether decisions differ depending on the type of display with Fisher’s Exact Test. We specifically analyzed two cases: with uncertainty (Dcum and Dnoncum) and without uncertainty (Dvis andDtext).
C1 C2
TO1 <0.001 *** <0.001 ***
TO2 <0.001 *** <0.001 ***
TO3 0.001 ** <0.001 ***
TO4 0.047 * 0.336
TO5 <0.001 *** <0.001 ***
Significance levels: p-value<0.001: ***,<0.01: **,<0.05: *
Table 4: P-values according to Fisher’s Exact Test for decisions depending on the design of train trip display.
Dcum vs. Dnoncum Dvis vs. Dtext
TO1 C1
0.002 **◦ 0.752
TO2 0.74 0.396
TO3 1 0.116
TO4 0.023 * 0.106
TO5 0.332 0.04 *
TO1 C2
1 1
TO2 1 0.115
TO3 0.593 0.729
TO5 0.839 0.32
Significance levels: p-value<0.001: ***,<0.01: **, ¡ 0.05: * Bonferroni corrected: p-value<0.0002: ◦◦◦,<0.002: ◦◦,<0.008: ◦
Table 5: P-values according toPost-hoc Fisher’s Exact Test for decisions depending on the type of delay display and depending on whether display is visual or text.
4.3 Dependence on the Existence of an Arrival Deadline
TO1 TO2 TO3 TO4 TO5
† <0.001 *** † 0.096 0.029 * 0.789 † 0.08
† includes the decision that both connections are of equal value Significance levels: p-value<0.001: ***,<0.01: **,<0.05: *
Table 6: P-values according toMcNemar Test for decisions depending on the time constraint.
Dcum &Dnoncum Dvis&Dtext
TO1 0.004 **
TO2 1 † 0.039 *
TO3 1 0.034 *
TO4 0.221 0.724
TO5 1 † 0.096
† includes the decision that both connections are of equal value Significance levels: p-value<0.001: ***,<0.01: **,<0.05: *
Table 7: P-values according to McNemar Test for decisions depending on the time constraint for designs with uncertainty (Dcum & Dnoncum) and without uncertainty (Dvis & Dtext).
Dcum Dnoncum Dvis Dtext TO1 0.023 * 0.248
TO2 1 † 0.059 0.48
TO3 1 0.505 0.046 *
TO4 1 0.248 0.134 0.617
TO5 1 0.48 1
† includes the decision that both connections are of equal value Significance levels: p-value<0.001: ***,<0.01: **,<0.05: *
Table 8: P-values according to McNemar Test for decisions depending on the time constraint for each design.
5 Decision Making Durations
Table 9: Decision Making Durations
D4 D1 D2 D3
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D4 D1 D2 D3
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T1C1
T1C2
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(a) TO1 C1
D4 D1 D2 D3
2060100140
!"#$" !%&' !()(%&' !*+,
D4 D1 D2 D3
10305070
T1C1
T1C2
!"#$" !%&' !()(%&' !*+,
(b) TO1 C2
D4 D1 D2 D3
050100150
D4 D1 D2 D3
20406080
!"#$" !%&' !()(%&' !*+,
!"#$" !%&' !()(%&' !*+,
T2C1
T2C2
(c) TO2 C1
D4 D1 D2 D3
050100150
D4 D1 D2 D3
20406080
!"#$" !%&' !()(%&' !*+,
!"#$" !%&' !()(%&' !*+,
T2C1
T2C2
(d) TO2 C2
D4 D1 D2 D3
020406080120
D4 D1 D2 D3
20406080120
T3C1
T3C2
!"#$" !%&' !()(%&' !*+,
!"#$" !%&' !()(%&' !*+,
(e) TO3 C1
D4 D1 D2 D3
020406080120
D4 D1 D2 D3
20406080120
T3C1
T3C2
!"#$" !%&' !()(%&' !*+,
!"#$" !%&' !()(%&' !*+,
(f) TO3 C2
D4 D1 D2 D3
050100150
D4 D1 D2 D3
02060100140
T4C1
T4C2
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!"#$" !%&' !()(%&' !*+,
(g) TO4 C1
D4 D1 D2 D3
050100150
D4 D1 D2 D3
02060100140
T4C1
T4C2
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!"#$" !%&' !()(%&' !*+,
(h) TO4 C2
D4 D1 D2 D3
20406080
D4 D1 D2 D3
050100150
T5C1
T5C2
!"#$" !%&' !()(%&' !*+,
!"#$" !%&' !()(%&' !*+,
(i) TO5 C1
D4 D1 D2 D3
20406080
D4 D1 D2 D3
050100150
T5C1
T5C2
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!"#$" !%&' !()(%&' !*+,
(j) TO5 C2
Figure 23: Decision Making Durations